Risk factors for carbapenem-resistant Pseudomonas aeruginosa infection in a tertiary care hospital in Serbia.

Introduction Pseudomonas aeruginosa is well-known cause of hospital infections with high morbidity and mortality rates [1]. According to the National Nosocomial Infections Surveillance System (NNISS), P. aeruginosa is responsible for approximately 8% of all hospital infections. It was the most frequent cause of ventilator-associated pneumonias (VAP), the fourthrated on the list of causes of hospital urinary infections, and fifth cause of surgical site infections according to frequency of occurence (2). Infections caused by P. aeruginosa are difficult to control and treat due to its high rate of resistance to antibiotics and to the limited number of available antibiotics with efficacy against P. aeruginosa. During the last decade, an increase in resistance to imipenem and meropenem was observed among many strains of Gram-negative bacteria, and especially among isolates of P. aeruginosa [3,4,5]. Numerous studies have also shown that carbapenem-resistant P. aeruginosa (CRPA) is frequently simultaneously resistant to other antipseudomonal antibiotics, making the treatment very difficult [6]. A number of risk factors for the emergence of CRPA-caused hospital infections was identified, including spending time in an intensive care unit and/or prior use of certain antibiotics [7,8,9,10]; however, for the majority of factors, the strength of the association was either low or equivocal. Sound knowledge of the risk factors and quantification of their influence on hospital infections are important for proper prevention and treatment of the CRPA-caused nosocomial infections. The aim of this study was to identify risk factors associated with the CRPA-caused hospital infections.